LONDON, NOV. 26 -- As the three men contending to succeed Margaret Thatcher wound up another round in their battle for 10 Downing Street, much of Britain's attention remained focused today on the prime minister it is about to lose, not the one it will soon get.

John Major's prospects got another boost as Thatcher's aides made it known she would be voting for her chancellor of the exchequer and former protege Tuesday when Conservative legislators try again to choose a new party leader, who will automatically serve as prime minister. Major's aggressive campaign has produced a bandwagon effect that seems to have brought him even with Michael Heseltine, the charismatic former defense secretary whose substantial showing in the party's first round of balloting last week forced Thatcher to resign.

Foreign Secretary Douglas Hurd is believed to be running third, and some insiders say his campaign is fading.

But while the feverish race entranced the 372 Tory lawmakers who will vote Tuesday, many other Britons remained disoriented by the sudden loss of the woman who had led their country for more than 11 years.

Two Thatcher loyalists handcuffed themselves to the front stoop of Heseltine's Belgravia townhouse late last week with a sign reading "Maggie Made Us Great. You Have Destroyed Us." A baffled child surveying the field vying to replace her reportedly asked, "But Daddy, can a man be prime minister?"

Aides say Downing Street had received 9,000 letters and more than 1,000 bouquets of flowers by Saturday, and five more sacks full of mail were delivered this morning. Thatcher moved her belongings out of the prime minister's residence today.

Hundreds of other loyalists -- mostly women, many of them tearful -- have jammed the phone lines at the Conservative Party's headquarters here to register their anger, according to a party spokesman. Some have returned their party membership cards, torn in half.

Newspapers and radio programs over the weekend were filled with intricately detailed accounts of what happened between Wednesday afternoon, when Thatcher declared defiantly that she would "fight on," and Thursday morning, when her office announced her resignation. The reports described emotionally wrenching sessions with supporters and a final cabinet meeting Thursday morning in which Thatcher and several of her ministers reportedly broke down and cried.

According to most of these accounts, it was not the party's elders -- the proverbial "men in gray suits" -- but a younger group of cabinet ministers who persuaded Thatcher to resign or face a humiliating defeat by Heseltine, a longtime bitter rival. And the key actor in her resignation appears to have been one of her most faithful supporters, Energy Secretary John Wakeham, who had just agreed to take over as her campaign chairman.

Several of the elders, including party chairman Kenneth Baker, House of Commons leader John MacGregor, chief whip Timothy Renton and Cranley Onslow, chairman of the 1922 Committee, the main body of the party's caucus, lunched with Thatcher that Wednesday.

They reportedly explored her options after last Tuesday's balloting, in which she outpolled Heseltine but fell four votes short of the majority plus 15 percent she needed for reelection under party rules. Some expressed fears that support for her was eroding, but none of them stated outright that she would have to resign, according to a senior aide.

The aide said she left for the House of Commons that afternoon still expecting to fight and win. But Wakeham said in a radio interview that before making a final decision, he insisted she meet individually with members of her cabinet in her cramped office adjoining the House chamber.

About a half-dozen of those members had met secretly by themselves the night before and concluded that Thatcher was finished. Several told her so in blunt terms Wednesday evening. Altogether, according to several accounts, about two-thirds of the 15 or so ministers she consulted individually told her she could not win.

Thatcher returned to Downing Street that night convinced she was in serious trouble. While three right-wing junior ministers rushed over to try to persuade her to hang on, her husband, Denis, took the other side. "He didn't want to see her humiliated," the aide said.

She retired to her private chambers that night leaning toward resignation and confirmed her intention early the next morning, the aide said.

Thatcher has maintained public silence on her departure, except for her bravura performance in the House of Commons Thursday after the announcement. Aides contend she has adopted a serene and philosophical attitude about her political demise.

"It's a rough old world, this," said an aide in describing her state of mind. "She's not in a position to grumble, and she isn't grumbling. . . . She doesn't want to go out in a wave of recrimination and backbiting. She's always said that the first law of politics is that the unexpected will happen."

Still, many supporters have said they believe Thatcher's real attitude is more like the one expressed by her daughter Carol, who called the party's abandonment of her mother "the most gutless act of treachery, after all she has done."

From behind the scenes, Thatcher was still seeking to manipulate the contest to succeed her by declaring through aides her support for Major, 47, whom she first picked out as a promising young lawmaker in 1984 after he reportedly engaged in a fierce argument with her over economic policy.

"She regards him as the man of the people," said the aide to Major. "He's in tune with ordinary people, and she's certainly backing him."

But the aide did not confirm a news story Sunday that Thatcher would resign her seat in Parliament if Heseltine wins the premiership. For one thing, the aide noted, that would force a by-election in her north London district of Finchley and could risk an embarrassing Labor Party seizure of the seat Thatcher has held for 31 years.

All three contenders for prime minister gave optimistic assessments of their chances -- so optimistic, that if all were correct, Tuesday's total vote would be at least 450, well above the 372 Conservative House members eligible to vote. Major's supporters claimed at least 160 votes, Heseltine's at least 180 and Hurd's more than 100.

While all three candidates are well qualified, one Tory lawmaker said, all three are considered to have major liabilities. Hurd, 60, is considered too old, too stuffy and too patrician, while Major is allegedly too young and too boring. Heseltine, 57, is considered too ruthlessly ambitious and has engendered bitter hatred among some party loyalists because of his successful campaign against Thatcher.